In a number of co-pending applications, an apparatus and method have been provided which seek to produce yarns having properties approaching those of ring spun yarn, only at significantly greater speeds and with other significant operational advantages including automatic elimination of lint fly or oily waste, and reduction in the number of process steps compared to ring spun yarn. Such methods and apparatus are shown in co-pending application Ser. No. 677,487 filed Dec. 3, 1984, 680,510 filed Dec. 11, 1984, 732,256 filed May 9, 1985, and 732,319 filed May 9, 1985.
The methods employed in the above-identified applications and in U.S. Pat. No. 4,507,913, issued Apr. 2, 1985, have come to be known by the name "vacuum spinning". It has been recognized that the yarn produced by advanced vacuum spinning techniques has a unique construction and appearance. The construction of the yarn can be described in a number of different manners including both independent and relative (to other spun yarn produced by other techniques) manners.
The yarn according to the present invention includes core fibers and wrapper fibers. The wrapper fibers are predominantly individual fibers, although there are some groups of wrapper fibers. The groups of wrapper fibers appear as non-uniform, non-consistent fiber groupings, and provide a relatively smooth surface. The core fibers, on the other hand, are essentially parallel with the wrapper fibers uniformly distributed therearound. The fasciated yarn according to the invention thus looks most like ring spun yarn of the commonly known yarns, although it is distinct in appearance from ring spun yarn too. For instance the yarn according to the invention looks more like ring spun yarn than core spun, open-end MJS, Toray, or DREF II prior art yarns. MJS means Munata Jet Spun Yarn.
The fasciated yarn according to the invention has, as set forth above, essentially parallel core staple fibers. There is a uniform distribution of staple fiber wrapper fibers around the core fibers, the wrapper fibers being wrapped at a helix angle of about 30.degree., and with about 20-30 percent of the fiber mass comprising wrapper fibers.
The fasciated yarn according to the invention can also be described as a yarn having a core of essentially parallel staple fibers with the wrapped staple fibers disposed around the core forming a helix angle in the range of about 30.degree.-50.degree., and the wrapped fibers are devoid of tucked or reverse wrapped fibers and are essentially devoid of auger or corkscrew appearing wrapped fibers. Rather the wrapped fibers have a smooth appearance.
The fasciated yarn according to the invention can be produced with the predominant proportion of staple fibers of the core and covering as non-thermoplastic staple fibers. While the predominant proportion of the core and wrapped fibers can be selected from the group consisting of cotton, wool, rayon, mohair, flax, ramie, silk, and blends thereof, the yarn according to the invention also can be constructed using some, or all, thermoplastic fiber, such as acrylic, polyester, and other thermoplastic fibers or blends thereof.
The yarn produced according to the present invention has surprising and desirable strength. For instance yarn produced according to the invention from a 1/18's count of 45 percent polyester and 55 percent wool will have a minimum gram break strength of about 500, while yarn according to the present invention with the same count made from 100 percent wool will have a minimum gram break strength of at least about 175. Thus even when made from 100 percent wool the yarn according to the present invention is suitable for making apparel fabrics.
It is the primary object of the present invention to provide a unique and desirable fasciated yarn having an appearance and properties comparable to those of ring spun yarn, but producible at increased speeds. This and other objects of the invention will become clear from an inspection of the detailed description of the invention, and from the appended claims.